Punching, striking, body locking, kneeing, kicking, pounding, flipping, elbowing, choking and taking someone down are all allowed inside the cage.
Welcome to the fierce world of mixed martial arts (MMA), where competitors brawl in a cage and go to the punishing extremes of knocking each other out using aggressive means while a crowd roars on in support.
Women cage fighters are increasingly drawing the crowds, many feeling there is nothing better than watching two fine physical specimens of the female variety attack each other.
Once the gate of the cage is shut, there is nowhere to hide.
This high-adrenaline art form is growing rapidly in Ireland and encompasses a range of different martial arts, such as karate, Thai boxing, judo, wrestling and jiu-jitsu.
Apart from the strenuous -- some say barbaric -- physical side of the sport, there is a considerable mental aspect, with fighters forced to make split-second tactical decisions.
Limerick woman Catherine Costigan is a world-class athlete who trains as hard as any Olympian, yet she has no public profile.
Nicknamed the Alpha Female, the 32-year-old is in optimum shape. She became a professional fighter in 2010 and is one of only two professional MMA fighters here.
Currently undefeated, she is ranked 15 in the world and has set her sights on becoming the world's number one in her 48kg category.
Her interest in martial arts came from watching Bruce Lee and John-Claude Van Damme movies with her father.
"I wasn't sporty in school as I never fitted in with team sports. I use to watch how Bruce Lee could beat an opponent twice his size," she says.
When she was 14, Catherine joined a karate/kickboxing club in Limerick, where she became a promising karate student.
In later years, the karate class changed to MMA training. "I could see that I was winning and beating men twice my side and people were telling me I was very good at it."
Catherine's coach, Dermot McGrath, is also her husband of seven years, which means that the weight of two people's dreams are on Catherine's shoulders.
The intense six-days-a-week training is the toughest part for Catherine. The fight itself, she says, is easier than all the work that goes before it.
"You train every day as you don't know how hard your opponent is training. If you slack in any way, you will set yourself up for failure.
"These girls are the genuine deal," she adds. "They want it just as bad as me, so when we are looking across that cage, it's war.
"I out-scramble my opponents and I move really fast, but I can only do that if I have the strength and the speed, and if I haven't trained it's not going to happen."
For Catherine, the perks of such unique training are the results she sees in her body and fitness.
"Any woman who says they want the perfect bikini body should do this," she says.
Catherine refutes charges that the sport is unladylike or encourages violence.
"It's not about beating the hell out of each other; it's strategy. It's less dangerous than boxing but, on the other hand, I'm an entertainer," she explains.
Nonetheless, her mother still has reservations about her daughter's choice of career and cannot yet bring herself to watch her fights.
Outside the cage, Catherine is happy to embrace her girlie side and turn prejudice on its head.
"I love to dress up. After fights I get dressed up and go out and feel fabulous, and people don't recognise me as they are so used to seeing me in my kickboxing clothes," she laughs.
Not getting equal financial reward to the men is another major downside to the sport.
"It doesn't make sense that women don't get paid the same as the men. I pay for most of my training and travel myself," she says.
To supplement her income, Catherine teaches MMA to more than 200 students, including some as young as four, at her martial arts school in Limerick, which has a 24-foot fighting cage.
"I teach women how to handle themselves with a man twice their size if they are attacked," she says.
Amanda English from Louth is an unlikely fighter and one of three amateur cage fighters in Ireland. A scientist by day, for a Dublin-based laboratory, she turns into a cage fighter after dark. She took up Thai boxing in 2007 to keep fit and became more competitive as she went on.
Training at least three days a week, she increases this to six days a week when in competition mode.
She is in training for a fight next month, where she will compete at 56kg. "The most difficult thing for me is finding the time to train while working full-time and studying part-time in the evening," she says.
In the best shape of her life, Amanda feels the efforts are worth it. "My cardio, energy, strength and stamina have increased dramatically.
"I have greater confidence as a result of learning these new skills and am involved now in teaching classes, something that I would have been too nervous to do before I began training."
If one athlete is overwhelmed by their opponent, the match is stopped.
"People see one sensationalistic clip of a knockout, but that is only one part of the sport," she says.
The 33-year-old's grandmother is her biggest supporter, and has attended two fights.
For many fighters, having a relationship with someone who doesn't understand it is tough so, like Catherine, Amanda's husband also competed.
And Like Catherine, she enjoys the glitzier things in life, too.
There are some social downsides to cage fighting, however.
"I bruise very easily and get a black eye on occasion. They always look worse that they are.
"Most of the injuries are superficial, like bruising, and takes a day or two to fade."
The Cage Warriors Fighting Championship 47 takes place on June 2 at The Helix, Dublin
Top fat-burning tip: Mix natural fat-free yogurt with protein powder to give you energy and curb appetite.
Diet: Catherine eats six times a day, every two hours and advises grazing on clean proteins. Breakfast is a protein drink in natural yogurt and oatmeal with a tablespoon of flaxseed. Mixed nuts, carrots, fruit, broccoli, fish oils and almonds are great snacks. Dinner is a portion of ovencooked chicken, half a potato and broccoli. If you eat the right food, says Catherine, you won’t crave junk and you’ll be a fat-burning machine.
Workouts: Trains intensely six days a week and her gruelling training regime involves circuit training, kettle bells, hill sprints and sparring.
Top fat-burning tip: Eating smaller meals at regular intervals works better for Amanda than eating fewer larger meals. This gives her plenty of energy to train well for longer and not get tired. As a result, she uses up more energy than she would if she started exercising when she was hungry and tired.
Diet: Amanda always starts the day with a good breakfast — usually porridge and fruit. She’ll have yogurt and fruit, or a banana on a slice of toast, at 11am, then a carbohydrate- based lunch such as pasta and a cereal bar before she trains at 7pm. Dinner is late and is mainly protein, such as a vegetable omelette. She boosts her protein intake with a protein drink.
Workouts: Amanda’s training involves sparring — a mix up of wrestling and Brazilian jiu-jitsu — and a strength and conditioning session involving cardio and weights.